/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | foam-extend: Open Source CFD
   \\    /   O peration     |
    \\  /    A nd           | For copyright notice see file Copyright
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of foam-extend.

    foam-extend is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by the
    Free Software Foundation, either version 3 of the License, or (at your
    option) any later version.

    foam-extend is distributed in the hope that it will be useful, but
    WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with foam-extend.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "backward2D2dt2Scheme.H"
#include "fvcDiv.H"
#include "fvMatrices.H"
#include "backwardDdtScheme.H"
#include <assert.h>

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace Foam
{

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

namespace fv
{

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

template<class Type>
scalar backward2D2dt2Scheme<Type>::deltaT_() const
{
    return mesh().time().deltaT().value();
}


template<class Type>
scalar backward2D2dt2Scheme<Type>::deltaT0_() const
{
    return mesh().time().deltaT0().value();
}


template<class Type>
scalar backward2D2dt2Scheme<Type>::deltaT0_(GeometricField<Type, fvPatchField, volMesh>& vf) const
{
    // Bug fix, Zeljko Tukovic: solver with outer iterations over a time-step
    // HJ, 12/Feb/2010
//     if (vf.oldTime().timeIndex() == vf.oldTime().oldTime().timeIndex())
    if
    (
        vf.oldTime().oldTime().timeIndex()
     == vf.oldTime().oldTime().oldTime().timeIndex()
    )
    {
        return GREAT;
    }
    else
    {
        return deltaT0_();
    }
}

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

template<class Type>
tmp<GeometricField<Type, fvPatchField, volMesh> >
backward2D2dt2Scheme<Type>::fvcD2dt2
(
    const GeometricField<Type, fvPatchField, volMesh>& vf
)
{
    dimensionedScalar rDeltaT2 =
        4.0/sqr(mesh().time().deltaT() + mesh().time().deltaT0());

    IOobject d2dt2IOobject
    (
        "d2dt2("+vf.name()+')',
        mesh().time().timeName(),
        mesh(),
        IOobject::NO_READ,
        IOobject::NO_WRITE
    );

    scalar deltaT = mesh().time().deltaT().value();
    scalar deltaT0 = mesh().time().deltaT0().value();

    scalar coefft   = (deltaT + deltaT0)/(2*deltaT);
    scalar coefft00 = (deltaT + deltaT0)/(2*deltaT0);
    scalar coefft0  = coefft + coefft00;

    if (mesh().moving())
    {
        notImplemented
        (
            type()
          + "::fvcD2dt2(const GeometricField<Type, fvPatchField, volMesh>& vf)"
        );

        return tmp<GeometricField<Type, fvPatchField, volMesh> >
        (
            new GeometricField<Type, fvPatchField, volMesh>
            (
                d2dt2IOobject,
                rDeltaT2*
                (
                    coefft*vf
                  - coefft0*vf.oldTime()
                  + coefft00*vf.oldTime().oldTime()
                )
            )
        );
    }
    else
    {
        return tmp<GeometricField<Type, fvPatchField, volMesh> >
        (
            new GeometricField<Type, fvPatchField, volMesh>
            (
                d2dt2IOobject,
                rDeltaT2*
                (
                    coefft*vf
                  - coefft0*vf.oldTime()
                  + coefft00*vf.oldTime().oldTime()
                )
            )
        );
    }
}


template<class Type>
tmp<GeometricField<Type, fvPatchField, volMesh> >
backward2D2dt2Scheme<Type>::fvcD2dt2
(
    const volScalarField& rho,
    const GeometricField<Type, fvPatchField, volMesh>& vf
)
{
    dimensionedScalar rDeltaT2 =
        4.0/sqr(mesh().time().deltaT() + mesh().time().deltaT0());

    IOobject d2dt2IOobject
    (
        "d2dt2("+rho.name()+','+vf.name()+')',
        mesh().time().timeName(),
        mesh(),
        IOobject::NO_READ,
        IOobject::NO_WRITE
    );

    scalar deltaT = mesh().time().deltaT().value();
    scalar deltaT0 = mesh().time().deltaT0().value();

    scalar coefft   = (deltaT + deltaT0)/(2*deltaT);
    scalar coefft00 = (deltaT + deltaT0)/(2*deltaT0);

    if (mesh().moving())
    {
        notImplemented
        (
            type()
          + "::fvcD2dt2"
          + "("
          + "const volScalarField& rho, "
          + "const GeometricField<Type, fvPatchField, volMesh>& vf"
          + ")"
        );

        dimensionedScalar halfRdeltaT2 = 0.5*rDeltaT2;

        tmp<volScalarField> rhoRho0 = rho + rho.oldTime();
        tmp<volScalarField> rho0Rho00 = rho.oldTime() +rho.oldTime().oldTime();

        return tmp<GeometricField<Type, fvPatchField, volMesh> >
        (
            new GeometricField<Type, fvPatchField, volMesh>
            (
                d2dt2IOobject,
                halfRdeltaT2*
                (
                    coefft*rhoRho0*vf
                  - (coefft*rhoRho0 + coefft00*rho0Rho00)*vf.oldTime()
                  + coefft00*rho0Rho00*vf.oldTime().oldTime()
                )
            )
        );
    }
    else
    {
        dimensionedScalar halfRdeltaT2 = 0.5*rDeltaT2;

        tmp<volScalarField> rhoRho0 = rho + rho.oldTime();
        tmp<volScalarField> rho0Rho00 = rho.oldTime() + rho.oldTime().oldTime();

        return tmp<GeometricField<Type, fvPatchField, volMesh> >
        (
            new GeometricField<Type, fvPatchField, volMesh>
            (
                d2dt2IOobject,
                halfRdeltaT2*
                (
                    coefft*rhoRho0*vf
                  - (coefft*rhoRho0 + coefft00*rho0Rho00)*vf.oldTime()
                  + coefft00*rho0Rho00*vf.oldTime().oldTime()
                )
            )
        );
    }
}


template<class Type>
tmp<fvMatrix<Type> >
backward2D2dt2Scheme<Type>::fvmD2dt2
(
    GeometricField<Type, fvPatchField, volMesh>& vf
)
{
    tmp<fvMatrix<Type> > tfvm
    (
        new fvMatrix<Type>
        (
            vf,
            vf.dimensions()*dimVol/dimTime/dimTime
        )
    );

    assert(  mesh().moving() == false );

    fvMatrix<Type>& fvm = tfvm();

    scalar deltaT = mesh().time().deltaT().value();

    scalar rDeltaT2 = 1.0/sqr(deltaT);

    vf.oldTime().oldTime().oldTime();

    if ( mesh().time().timeIndex() == 1 )
    {
        scalar coefft   = 1;
        scalar coefft0  = -2;
        scalar coefft00 = 1;

        coefft += coefft00;

        fvm.diag() = (coefft*rDeltaT2)*mesh().V();

        fvm.source() = rDeltaT2*mesh().V()*
        (
            - coefft0*vf.oldTime().internalField()
        );
    }
    else if ( mesh().time().timeIndex() == 2 )
    {
        scalar coefft   = 2;
        scalar coefft0  = -5;
        scalar coefft00 = 4;
        scalar coefft000 = -1;

        coefft0 += coefft000;

        fvm.diag() = (coefft*rDeltaT2)*mesh().V();

        fvm.source() = rDeltaT2*mesh().V()*
        (
            - coefft0*vf.oldTime().internalField()
            - coefft00*vf.oldTime().oldTime().internalField()
        );
    }
    else
    {
        scalar coefft   = 2;
        scalar coefft0  = -5;
        scalar coefft00 = 4;
        scalar coefft000 = -1;

        fvm.diag() = (coefft*rDeltaT2)*mesh().V();

        fvm.source() = rDeltaT2*mesh().V()*
        (
            - coefft0*vf.oldTime().internalField()
            - coefft00*vf.oldTime().oldTime().internalField()
            - coefft000*vf.oldTime().oldTime().oldTime().internalField()
        );
    }

    return tfvm;
}


template<class Type>
tmp<fvMatrix<Type> >
backward2D2dt2Scheme<Type>::fvmD2dt2
(
    const dimensionedScalar& rho,
    GeometricField<Type, fvPatchField, volMesh>& vf
)
{
    tmp<fvMatrix<Type> > tfvm
    (
        new fvMatrix<Type>
        (
            vf,
            rho.dimensions()*vf.dimensions()*dimVol
            /dimTime/dimTime
        )
    );

    fvMatrix<Type>& fvm = tfvm();

    scalar deltaT = mesh().time().deltaT().value();
    scalar deltaT0 = mesh().time().deltaT0().value();

    scalar coefft   = (deltaT + deltaT0)/(2*deltaT);
    scalar coefft00 = (deltaT + deltaT0)/(2*deltaT0);

    scalar rDeltaT2 = 4.0/sqr(deltaT + deltaT0);

    if (mesh().moving())
    {
        notImplemented
        (
            type()
          + "::fvcD2dt2"
          + "("
          + "const dimensionedScalar& rho, "
          + "GeometricField<Type, fvPatchField, volMesh>& vf"
          + ")"
        );
    }
    else
    {
        fvm.diag() = (coefft*rDeltaT2)*mesh().V()*rho.value();

        fvm.source() = rDeltaT2*mesh().V()*rho.value()*
        (
            (coefft + coefft00)*vf.oldTime().internalField()
          - coefft00*vf.oldTime().oldTime().internalField()
        );
    }

    return tfvm;
}


template<class Type>
tmp<fvMatrix<Type> >
backward2D2dt2Scheme<Type>::fvmD2dt2
(
    const volScalarField& rho,
    GeometricField<Type, fvPatchField, volMesh>& vf
)
{
    tmp<fvMatrix<Type> > tfvm
    (
        new fvMatrix<Type>
        (
            vf,
            rho.dimensions()*vf.dimensions()*dimVol
            /dimTime/dimTime
        )
    );

    fvMatrix<Type>& fvm = tfvm();

    scalar deltaT = mesh().time().deltaT().value();
    scalar deltaT0 = mesh().time().deltaT0().value();

    scalar coefft   = (deltaT + deltaT0)/(2*deltaT);
    scalar coefft00 = (deltaT + deltaT0)/(2*deltaT0);

    scalar rDeltaT2 = 4.0/sqr(deltaT + deltaT0);

    if (mesh().moving())
    {
        notImplemented
        (
            type()
          + "::fvmD2dt2"
          + "("
          + "const volScalarField& rho, "
          + "const GeometricField<Type, fvPatchField, volMesh>& vf"
          + ")"
        );
    }
    else
    {
        scalar halfRdeltaT2 = 0.5*rDeltaT2;

        tmp<scalarField> rhoRho0 =
            (rho.internalField() + rho.oldTime().internalField());

        tmp<scalarField> rho0Rho00 =
        (
            rho.oldTime().internalField()
          + rho.oldTime().oldTime().internalField()
        );

        fvm.diag() = (coefft*halfRdeltaT2)*mesh().V()*rhoRho0;

        fvm.source() = halfRdeltaT2*mesh().V()*
        (
            (coefft*rhoRho0 + coefft00*rho0Rho00)
           *vf.oldTime().internalField()

          - (coefft00*rho0Rho00)
           *vf.oldTime().oldTime().internalField()
        );
    }

    return tfvm;
}


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace fv

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

} // End namespace Foam

// ************************************************************************* //
